1. Field of the Invention
The invention is based on a machine tool of the type having a tool part supported by a housing and having an adjustment part associated therewith, in which a workpiece can be introduced between the tool part and the adjustment part for machining.
2. Description of the Prior Art
In a known machine tool of this generic type disposition, an adapter is disposed on a housing via a coupling and is rotatable about the housing axis; from the adapter, a pivot beam leads to an intermediate rotary bearing, as a result of which the housing can be rotated in its plane formed by its axis of rotation. The intermediate rotary bearing is in turn disposed on a cantilevered beam, which is retained on its other end. The housing that receives the machine tool is thus in intrinsically rotatable as well as pivotable in the plane defined by its axis, and this arbitrary adjustment can be accomplished via a handle disposed on the housing. The connection for the external energy, which can be electrical, pneumatic or hydraulic, is made via the intermediate rotary bearing and the pivot beam to the adapter, and from there into the housing. Thus in this energy supply system, at least two rotary bearings have to be overcome, which naturally leads to sealing problems. The housing of the machine tool is embodied as tongs, and in manipulation, the workpiece is thrust between the tool part and the abutment part for machining; the flexibility lent by the rotary bearings to the handling device defined by the cantilevered beam, the intermediate rotary bearing, the pivot beam and the coupling and the adapter is meant to facilitate delivering the workpiece to the tool or the tool to the workpiece.
As is known from another handling device (German Published, Nonexamined Patent Application DE-OS 32 25 108), a machine tool of this kind is often suspended from a crane or the like to gain greater freedom of motion; the rotation of the machine tool about its own axis is much less decisive than rotation about an axis that passes through its center of gravity. Despite the advantage of accommodating the energy supply lines via the pivot beam to the housing and the attendant advantage that the supply lines are spaced apart from the actual machining point, problems still exist in the free delivery of the handling device, whose adjustment must in each case be done from the handle disposed on the housing.
Still another handling device is known (DE-OS 38 40 163) in which, in contrast to the invention, the workpiece is not insertable between the tool part and the abutment part; the external energy is not supplied via lines extending inside the intermediate rotary bearing; the intermediate rotary bearing is not disposed directly on the housing, and thus its axis of rotation extends at a distance from the center of gravity of the housing; and there is no actuation handle on the intermediate rotary bearing. The resultant disadvantages are self-evident.
In still another known handling device (U.S. Pat. No. 4,677,727), decisive characteristics of the present invention are also lacking, since the workpiece cannot be inserted for the sake of being machined between the tool part and the abutment part, and retaining devices that engage the intermediate rotary bearing at the end of a cantilevered beam are provided that have an intermediate rotary bearing connected to the housing. Moreover, the supply of external energy is not accomplished via lines extending inside the intermediate rotary bearing, and there is no actuation handle disposed on the intermediate rotary bearing. Hence this known handling device is hard to manipulate and is far less widely usable.
The machine tool of the invention has the advantage over the prior art of one further degree of freedom in delivering the machine tool by means of the handling device of the invention, and furthermore that this delivery motion is better and more securely controllable as a result of the disposition of the actuation handle on the intermediate rotary bearing.
Because the intermediate rotary bearing is disposed directly on the housing, compared to the generic machine tool, not only is one rotary bearing that has to be overcome by the energy supply omitted, but greater strength with improved quality of guidance of the handling device is also achieved.
In an advantageous feature of the invention, a tool part such as a switch or a mechanically actuated valve, by which the energy supply is controllable, is disposed in the access range of the actuation handle. The connection of the supply line for the external energy can either be accomplished via a handle or provided at some other point of the housing of the intermediate rotary bearing.
In an additional feature of the invention, the retaining device has a bracket or the like for the engagement of the cantilevered cable or the like, whose direction of force is rotatable about the axis of rotation of the retaining device. The machine tool can be delivered extremely flexibly in combination with the handle on the intermediate rotary bearing as well as one additional handle on the housing.
In another advantageous feature of the invention, the intermediate rotary bearing has a pivot pin, secured to the housing, on which a rotatable cuff is supported in a sealed fashion, on which cuff the cantilevered beam or support arm and the actuation handle are secured.
In a further advantageous feature of the invention, the energy supply lines connected to the housing of the intermediate rotary bearing.
In an additional feature of the invention, the abutment part is correspondingly disposed pivotably in the housing from of a working position, determined by a stop, to a free position. Thus in the free position, both the abutment and the tool can be more easily replaced.
In a feature of the invention related to this, a spring engages the abutment part in the direction of the working position, so that the free position can be set only after the spring is overcome.
In another feature of the invention related to this, an actuation handle is provided on the abutment part, with which not only is the housing adjustable but also as needed the abutment part is pivotable relative to the housing. The pivot axis of the abutment part is offset from the work axis of the machine tool, so that in the working function, the abutment part is pressed against its stop.